I would fleece it and wrap the trunk so that it doesn't get any more frost damage. If it is in a pot, be sure to wrap the pot in bubble wrap, too. Remove the fleece in warm weather, but not the wrap. In late spring, when it is sprouting vigorously, you can remove the wrap, and prune off anything that isn't sprouting. Hopefully, it will start blooming and bearing again next year, but if the damage is severe, plan on another year or two. A mild feed with ericaceous fertilizer will help it to recover faster.